Recently, the sizes of the images taken in from cameras and the images output to LCDs have been increased, and therefore the image sizes handled by various equipment such as cameras, mobile terminals, and HDD recorders have been extremely increased. Correspondingly, the data volume transferred between LSIs and LCDs has been drastically increasing. For example, when the size of an image is changed from WVGA (865×480) to HD (1920×1080), the transferred data volume is increased by nearly five times. Moreover, the increase in the volume of the data that flows in a data signal line also largely affects the power consumption required for I/O of the signal line so as to be approximately proportional to the above described increase.
In order to take a measure against the above described problem, the techniques for reducing the volume of transferred data have been conventionally known. For example, in the data transfer device described in Patent Literature 1, the information of an upper part data in which the same values are continued is generated as the information of a set of the data value of that part and the number of the continuous data, thereby reducing the volume of the transferred data.
In an image display device described in Patent Literature 2, after color decrease processing which reduces the volume of data is carried out, Haffman encoding processing is carried out to compress the volume of the data.
Citation List
    Patent Literature 1: Japanese Patent Laid-Open No. 2006-163201    Patent Literature 2: Japanese Patent Laid-Open No. 2005-55825